Carrier guide and firearm

ABSTRACT

Firearms having a carrier assembly, buffer systems, and methods, having a carrier spindle, carrier saddle, or both, to reduce carrier tilt or wobble, reduce wear, or both. A carrier spindle can be located forward of the buffer spring, buffer weight, or both, and aft of the carrier assembly, and can slidably engage the carrier assembly. A spindle spring can bias the carrier spindle aft from the carrier assembly. In some embodiments, a taper on the carrier spindle facilitates separation of the lower receiver from the upper receiver. In some embodiments, the spindle spring is a helical spring that is loaded in compression and pushes the carrier spindle aftward. Some embodiments include a carrier saddle that supports the aft end of the carrier assembly. The carrier saddle can be raised, have a concave top surface, be made of a softer material, have dimensions within certain ranges, or a combination thereof.

RELATED PATENT APPLICATIONS

This patent application claims priority to U.S. Provisional Patent Application No. 61/936,022, filed on Feb. 5, 2014, titled CARRIER GUIDE AND FIREARM, which has at least one inventor in common with the current patent application and the same assignee. The contents of this priority provisional patent application are incorporated herein by reference.

FIELD OF THE INVENTION

Various embodiments of this invention relate to firearms. Particular embodiments relate to firearms having carrier assemblies.

BACKGROUND OF THE INVENTION

Firearms have been used for several centuries for various purposes including as weapons for warfare, law enforcement, self defense, hunting, and target practice. Although many new weapons and weapon systems have been developed, firearms are still widely used and soldiers are trained in firearm use and carry firearms in essentially all armies throughout the world. Over time, firearms have been improved in many ways, but opportunities for improvement still exist in particular areas and for particular aspects of these devices.

Firearms have been constructed with a bolt assembly and a carrier assembly, or with a bolt carrier group, and a main buffer spring. In a number of embodiments, when such a firearm is discharged, the bolt assembly and the carrier assembly or the bolt carrier group are propelled rearward by the products of combustion and compress the main buffer spring. The main buffer spring then pushes the bolt assembly and the carrier assembly or the bolt carrier group forward, which loads another round from the magazine into the chamber for firing. In addition to loading the next round, the buffer spring absorbs some of the recoil from firing the weapon.

In a number of prior art firearms, when the trigger is pulled and the bullet is fired, gas from the bullet discharge pushes the carrier group aft. As the bolt carrier group, for example, moves aft, the aft part or end of the bolt carrier group has tended to tilt down (carrier tilt), for instance, due to gravity or other forces (e.g., pressure coming from the top of the carrier group), has wobbled (e.g., side to side) within the upper receiver that contains the bolt carrier group (e.g., due to misalignment between the bolt carrier group and the upper receiver), or both. This has caused misalignment, for example, of the bolt carrier group. In a number of prior art firearms, the bolt carrier group has moved aft and engaged the main buffer or buffer weight and the main buffer spring, for example. In a number of embodiments, the main buffer spring suppresses the recoil of the rifle, for example, as well as returning the bolt carrier group forward. Further, in some cases, tilt or wobble has occurred when the buffer spring returns the bolt carrier group forward.

Carrier tilt and wobble and misalignment of the bolt carrier group has caused accelerated wear, for example, of the upper receiver, the lower receiver, the buffer tube, the bolt carrier group, or a combination thereof. In addition, carrier tilt and wobble and misalignment of the bolt carrier group has reduced accuracy of the firearm. Needs or potential for benefit or improvement exist for firearms wherein carrier tilt or wobble is avoided or reduced.

The problem of carrier tilt or wobble has been addressed by adding an elongated head to the buffer (i.e., the buffer weight), aft of the bolt carrier group, to form an anti-tilt buffer. The elongated head of an anti-tilt buffer has been configured with a close fit inside the bolt carrier group, guiding the bolt carrier group as the firearm is discharged, which reduces or eliminates contact and wear between the bolt carrier group and the buffer tube, at least at the aft end of the bolt carrier group. Anti-tilt buffers, however, make it difficult to open the gun because the elongated head and the connection with the bolt carrier group can interfere with separation of the upper receiver from the lower receiver, for instance. Needs or potential for benefit or improvement exist for firearms wherein carrier tilt or wobble is avoided or reduced but wherein the opening of the gun is not precluded and separation of the upper receiver from the lower receiver is not blocked or encumbered. Needs or potential for benefit or improvement exist for firearms that are smoother in operation, that operate with less friction, that have less misalignment between moving parts, that avoid or reduce wobble between parts, that operate with less wear, that last longer, that are more accurate, or a combination thereof, as examples. Room for improvement exists over the prior art in these and other areas that may be apparent to a person of skill in the art having studied this document.

SUMMARY OF PARTICULAR EMBODIMENTS OF THE INVENTION

This invention provides, among other things, firearms with improved systems and methods of reducing tilt or wobble of the bolt assembly, carrier assembly, or bolt carrier group, for example, within the buffer tube. In a number of firearms, as the bolt carrier group, for example, moves aft, the tilt downward of the aft part or end of the bolt carrier group is reduced, wobble within the upper receiver is reduced, or both. In a number of embodiments, this reduces misalignment, for example, of the bolt carrier group with the buffer tube. Further, in some embodiments, tilt or wobble is reduced when the buffer spring returns the bolt carrier group forward. In a number of embodiments wear is reduced, for example, of the upper receiver, the lower receiver, the bolt carrier group, the buffer tube, or a combination thereof. In various embodiments, carrier tilt or wobble is avoided or reduced. Further, in some embodiments, accuracy of the firearm is improved.

In a number of embodiments, a carrier spindle fits (e.g., with a close fit) inside the carrier assembly or the bolt carrier group, for example, guiding the carrier assembly or the bolt carrier group as the firearm is discharged, which reduces or eliminates contact and wear between the carrier assembly or the bolt carrier group and the buffer tube, at least at the aft end of the carrier assembly or the bolt carrier group. Further, in a number of embodiments, a carrier saddle (e.g., a raised carrier saddle) supports an aft end of the carrier assembly or the bolt carrier group, for example, guiding the carrier assembly or the bolt carrier group as the firearm is discharged, which reduces or eliminates contact and wear between the carrier assembly or the bolt carrier group and the buffer tube, at least at the aft end of the carrier assembly or the bolt carrier group. Some embodiments have a carrier spindle and a carrier saddle, but other embodiments have a carrier spindle and no carrier saddle or a carrier saddle and no carrier spindle.

In various embodiments, the gun can readily be opened without interference during separation of the upper receiver from the lower receiver. Thus, in a number of embodiments, carrier tilt or wobble is avoided or reduced but the opening of the gun is not precluded and separation of the upper receiver from the lower receiver is not blocked or encumbered. In certain embodiments, the firearms are smoother in operation, operate with less friction, have less misalignment between particular moving parts, avoid or reduce wobble between certain parts, operate with less wear, last longer, are more accurate, or a combination thereof, as examples.

Other embodiments, besides firearms, include methods of configuring, obtaining, or providing a firearm having less carrier tilt or wobble that particular alternatives. In a number of embodiments, improvements to firearms herein provide for firearms that are more reliable, that last longer, that are more adaptable, that can be used in conditions that are more extreme, that handle abuse well, that work better, that are easier to use, that are easier to maintain, that are less expensive to manufacture, that have a lower lifecycle cost, that offer more options for use, that can be fired more easily for a longer period of time, that are more accurate whether a single shot or multiple shots are fired, or a combination thereof, in comparison with certain alternatives.

Specific embodiments include various firearms that each include, for example, a carrier assembly, a carrier spindle, and a spindle spring. In a number of embodiments, a helical spindle spring, for example, is located between the carrier spindle and the carrier assembly, pushes the carrier spindle, for instance, aftward, away from the carrier assembly, or a combination thereof. In various embodiments, for example, the helical spindle spring is loaded in compression. Moreover, in a number of embodiments, the carrier spindle is at least partially aft of the carrier assembly. Further, in various embodiments, the carrier spindle slidably engages the carrier assembly.

In addition, some such embodiments include a buffer weight, a main buffer spring, or both. In a number of embodiments, for example, the buffer weight is aft of the carrier spindle, the main buffer spring is aft of the buffer weight, or both. Further still, in various embodiments the main buffer spring is aft of the carrier assembly. Even further, in some embodiments, the main buffer spring is stiffer than the (e.g., helical) spindle spring. Still further, in a number of embodiments, the carrier spindle fits inside the carrier assembly when the firearm is assembled.

Various embodiments include, for example, a barrel through which bullets are fired. In some embodiments, for instance, the carrier spindle includes a length parallel to an axis of the barrel, a forward end, and an aft end, and the aft end has a larger major lateral dimension than the forward end. Moreover, in some embodiments, the forward end has a uniform major lateral dimension over a majority of the length of the carrier spindle. Further, in some embodiments, the aft end of the carrier spindle includes a taper. Still further, in a number of embodiments, the firearm includes an upper receiver and a lower receiver. Even further, in certain embodiments, the taper pushes the carrier spindle forward when the upper receiver is separated from the lower receiver.

In some embodiments, the firearm includes a buffer tube. Further, in various embodiments, when the firearm is discharged, the carrier spindle guides the carrier assembly into the buffer tube, the carrier spindle acts to reduce carrier tilt within the firearm, or both. Further, certain embodiments include, for example, a raised carrier saddle that supports an aft end of the carrier assembly.

Other specific embodiments include various firearms that include, for example, a carrier assembly, a buffer spring, and a carrier saddle, for instance, that supports the aft end of the carrier assembly. In certain such embodiments, for example, the carrier assembly has an aft end, and the buffer spring biases the carrier assembly forward. Moreover, in various embodiments, the carrier saddle that supports the aft end of the carrier assembly is raised.

A number of such embodiments include, for example, a buffer weight, for instance, aft of the carrier assembly. Further, in some embodiments, the buffer spring is aft of the buffer weight. Still further, in various embodiments, the firearm includes an upper receiver and a lower receiver. Even further, in some embodiments, the lower receiver includes the raised carrier saddle. Further still, in certain embodiments, for instance, the raised carrier saddle is integral with the lower receiver. Even further still, in some embodiments, the firearm includes a buffer tube, and when the firearm is discharged, the (e.g., raised) carrier saddle guides the carrier assembly into the buffer tube. Moreover, in various embodiments, the (e.g., raised) carrier saddle acts to reduce carrier tilt within the firearm.

In some embodiments, the carrier saddle includes a concave top surface (e.g., raised) that supports the aft end of the carrier assembly. Further, in some embodiments, the top surface of the carrier saddle (e.g., that supports the aft end of the carrier assembly) includes an overall top surface lateral dimension that is between 25 percent and 75 percent of an overall lateral dimension of the carrier assembly at the aft end. Still further, in some embodiments, the top surface that supports the aft end of the carrier assembly includes an overall top surface longitudinal dimension that is less than the overall lateral dimension of the carrier assembly at the aft end. Even further, in some embodiments, the overall top surface longitudinal dimension is between ⅛ inch and the overall lateral dimension of the carrier assembly at the aft end, for example. Even further still, in various embodiments, the raised carrier saddle consists of a material having a lower hardness than a hardness of the carrier assembly at the aft end. Still further, in certain embodiments, the raised carrier saddle consists of a material having a significantly lower hardness than a hardness of the carrier assembly at the aft end.

In still other specific embodiments, a firearm includes, for example, an upper receiver, a lower receiver, a carrier assembly, a buffer spring, and a raised carrier saddle. In a number of embodiments, for example, the lower receiver includes a buffer tube, the carrier assembly is located in the upper receiver, the carrier assembly has an aft end, or a combination thereof. Further, in various embodiments, the buffer spring is located in the buffer tube, in the lower receiver, aft of the aft end of the carrier assembly, or a combination thereof. Still further, in a number of embodiments, the raised carrier saddle supports the aft end of the carrier assembly. Even further, in various embodiments, for instance, when the firearm is discharged, the raised carrier saddle guides the carrier assembly, for example, into the buffer tube, the raised carrier saddle acts to reduce carrier tilt within the firearm, or both. In addition, various other embodiments of the invention are also described herein, and other benefits of certain embodiments may be apparent to a person of skill in this area of technology.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings provided herewith illustrate, among other things, examples of certain aspects of particular embodiments. Other embodiments may differ. Various embodiments may include aspects shown in the drawings, described in the specification (including the claims), known in the art, or a combination thereof, as examples. Other embodiments, however, may differ.

FIG. 1 is a right-side cross-sectional view of an embodiment of a firearm that includes a carrier spindle;

FIG. 2 is a detail right-side cross-sectional view of part of the firearm of FIG. 1 showing, among other things, the lower receiver, most of the upper receiver, the main buffer spring, the buffer weight, the carrier spindle, and the bolt carrier group of the firearm, including the carrier assembly;

FIG. 3 is the detail right-side cross-sectional view of part of the firearm of FIG. 2 except showing the upper receiver partially separated from the lower receiver of the firearm;

FIG. 4 is a detail right-side cross-sectional view of part of another embodiment of a firearm, this embodiment having a carrier spindle and a carrier saddle, this view showing the same part of the firearm as FIG. 2, and this view also showing, among other things, the lower receiver, most of the upper receiver, the carrier assembly, the main buffer spring, and the buffer weight of the firearm;

FIG. 5 is the detail right-side cross-sectional view of part of the firearm of FIG. 4 except showing the upper receiver partially separated from the lower receiver of the firearm; and

FIG. 6 is an isometric top, front, right-side view of part of the lower receiver of the firearm of FIGS. 4-5 illustrating, among other things, the carrier saddle.

DETAILED DESCRIPTION OF EXAMPLES OF EMBODIMENTS

This patent application describes, among other things, examples of certain embodiments, and certain aspects thereof. Other embodiments may differ from the particular examples described in detail herein. Various embodiments are or concern firearms, for example, having improvements over the prior art. Different embodiments include firearms, mechanisms for firearms, and methods that provide for less carrier tilt or wobble of the carrier assembly or bolt carrier group within firearms, as examples.

In various embodiments, a firearm (e.g., 10, 40, shown in FIGS. 1-5) includes a carrier assembly (e.g., 26, 46), for instance, of a bolt carrier group (e.g., 27, 47), and a carrier spindle (e.g., 25, 45) that is located, for example, at least partially aft of the carrier assembly (e.g., 26, 46). As used herein, “aft” means the direction opposite the direction that the bullet is traveling in when the bullet leaves the firearm (e.g., 10, 40). In contrast, as used herein, “forward” means the direction that the bullet is traveling in when the bullet leaves the firearm (e.g., 10, 40). Further, as used herein, a first component or assembly is considered to be aft of a second component or assembly if the center of mass of the first component or assembly is aft of the center of mass of the second component or assembly.

In a number of embodiments, when the trigger of the firearm (e.g., 10, 40) is pulled and the bullet is fired, gas from the bullet discharge pushes the carrier assembly (e.g., 26, 46) or the bolt carrier group (e.g., 27, 47) aft. As the bolt carrier group (e.g., 27, 47) moves aft, in various embodiments, the aft part (e.g., aft end 39 of carrier assembly 26 or aft end 59 of carrier assembly 46) of the bolt carrier group (e.g., 27, 47) is supported and guided, at least in part, by the carrier spindle (e.g., 25, 45), for example, into the buffer tube (e.g., 22). In a number of embodiments, this partially, significantly, or substantially prevents the bolt carrier group (e.g., 27, 47) from tilting down (carrier tilt) due to gravity, pressure coming from the top of the carrier group, or both, as examples. In some embodiments, the carrier spindle (e.g., 25, 45) also corrects (e.g., at least partially) any misalignment of the bolt carrier group and the upper receiver (e.g., 11), which in turn, partially, significantly, or substantially prevents the bolt carrier group (e.g., 27, 47) from wobbling side to side or wobbling up and down as the carrier moves aft.

In various embodiments, the carrier assembly (e.g., 26, 46), the bolt carrier group (e.g., 27, 47), or both, continues to move aft and engages the (e.g., main) buffer weight (e.g., 23), (e.g., main) buffer spring (e.g., 21), or both. In a number of embodiments, the main buffer spring (e.g., 21), for example, suppresses the recoil of the rifle (e.g., firearm 10 or 40), for example, returns the carrier assembly (e.g., 26, 46), the bolt carrier group (e.g., 27, 47), or both, forward, or a combination thereof. Moreover, in various embodiments, during this forward motion, the carrier spindle (e.g., 25, 45) partially, significantly, or substantially prevents the carrier assembly (e.g., 26, 46), the bolt carrier group (e.g., 27, 47), or both from tilting or wobbling (e.g., side to side, up and down, or both).

In a number of embodiments, the carrier spindle (e.g., 25, 45) slidably engages a component of the firearm, for instance, the bolt carrier group or the carrier assembly (e.g., 26, 46). In certain embodiments, the carrier spindle (e.g., 25, 45) slides inside the carrier assembly (e.g., 26, 46) or bolt carrier group (e.g., 27, 47) when the carrier assembly (e.g., 26, 46) or bolt carrier group (e.g., 27, 47) moves aft when a shot is fired. In a number of embodiments, the carrier spindle (e.g., 25, 45) has a close fit with the carrier assembly (e.g., 26, 46) or bolt carrier group (e.g., 27, 47) and guides the carrier assembly (e.g., 26, 46) or bolt carrier group (e.g., 27, 47).

In particular embodiments, where a “close fit” is indicated herein, the clearance between the two parts, for example, the diametrical clearance between the forward end (e.g., 32, 52) of the carrier spindle (e.g., 25, 45) and the aft end (e.g., 39, 59) of the bolt carrier group (e.g., 27, 47) or carrier assembly is less than 0.10, less than 0.070, less than 0.050, less than 0.040, less than 0.030, less than 0.020, less than 0.015, less than 0.012, less than 0.010, less than 0.009, less than 0.008, less than 0.007, less than 0.006, or less than 0.005 inches, as examples, or within a range between two such clearances, as other examples. In different embodiments, the carrier spindle (e.g., 25, 45) is made of metal, for example, steel, stainless steel, aluminum, bronze, copper, brass, or titanium, or an alloy thereof, while in other embodiments, the carrier spindle (e.g., 25, 45) is made of plastic (e.g., nylon, polyurethane, or polyethylene. In some embodiments, the carrier spindle (e.g., 25, 45) is solid, while in other embodiments, the carrier spindle is hollow (not shown).

Further, in certain embodiments, the firearm (e.g., 10, 40) includes a main buffer spring (e.g., 21), for instance, aft of the carrier spindle (e.g., 25, 45). Further, in some embodiments, the firearm (e.g., 10, 40) includes a buffer weight (e.g., 23), for example, aft of the carrier spindle (e.g., 25, 45), for instance, between the carrier spindle (e.g., 25, 45) and the main buffer spring (e.g., 21). In particular embodiments, the buffer weight (e.g., 23) and the carrier spindle (e.g., 25, 45) are located between the main buffer spring (e.g., 21) and the carrier assembly (e.g., 26, 46) or bolt carrier group (e.g., 27, 47). In certain embodiments, the buffer weight (e.g., 23) and the carrier spindle (e.g., 25, 45) are in contact with each other, for example, when the firearm (e.g., 10, 40) is ready to be fired. Even further, in a number of embodiments, the main buffer spring (e.g., 21) is located aft of the buffer weight (e.g., 23).

Still further, some embodiments include a spindle spring (e.g., 24), for example, located between the carrier spindle (e.g., 25, 45) and the carrier assembly (e.g., 26, 46). In certain embodiments, the spindle spring (e.g., 24) surrounds or is concentric with (or both) the forward end (e.g., 32, 52) of the carrier spindle (e.g., 25, 45), for example, as shown. Even further, in particular embodiments, the spindle spring (e.g., 24) is located partially or at least partially inside the carrier assembly (e.g., 26, 46) or the bolt carrier group (e.g., 27, 47), for instance. In some embodiments, the main buffer spring (e.g., 21), the spindle spring (e.g., 24), or both, is a helical spring (e.g., as shown). In particular embodiments, the spindle spring (e.g., 24) pushes the carrier spindle (e.g., 25, 45), for instance, away from the carrier assembly (e.g., 26, 46). In certain embodiments, the spindle spring (e.g., 24) biases the carrier spindle (e.g., 25, 45) aftward (i.e., in the aft direction), for example. In various embodiments, the main buffer spring (e.g., 21), the spindle spring (e.g., 24), or both, are loaded in compression (e.g., when the firearm (e.g., 10, 40) is fired, or in some cases (e.g., to a lesser extent), also when the firearm (e.g., 10, 40) is assembled and ready for firing). An example is shown.

In various embodiments, the main buffer spring (e.g., 21) is longer than the spindle spring (e.g., 24), for instance, in the direction of the axis of the helix of the spring, or in a direction parallel to the barrel (e.g., 13) of the firearm. Further, in some embodiments, the main buffer spring (e.g., 21) is stiffer than the spindle spring (e.g., 24), the spindle spring (e.g., 24) is made of a smaller diameter wire, or both. In other embodiments, however, the main buffer spring (e.g., 21) is less stiff than the spindle spring (e.g., 24), or in certain embodiments, the main buffer spring (e.g., 21) and the spindle spring (e.g., 24) have a stiffness that is equal or substantially equal, as other examples. As used herein, unless stated otherwise, “equal” means equal to within 5 percent, and “substantially equal” means equal to within 10 percent. Further still, in a number of embodiments, the main buffer spring (e.g., 21) and the spindle spring (e.g., 24) have a common axis (e.g., center of the helix). As used herein, two spring axes are considered to be in common if the axes of the two springs fall on the same line (i.e., when the firearm (e.g., 10, 40) is assembled and ready for firing) to within ¼ inch over the length of the two springs. In other embodiments, the main buffer spring (e.g., 21) and the spindle spring (e.g., 24) have a common axis to within ⅛, 3/16, 5/16, ⅜, or ½ inch, as other examples.

In a number of embodiments, the main buffer spring (e.g., 21), the spindle spring (e.g., 24), or both, are made of metal, for example, steel or stainless steel. In some embodiments, however, the main buffer spring (e.g., 21), the spindle spring (e.g., 24), or both, are air springs. Further, in some embodiments, the main buffer spring (e.g., 21), the spindle spring (e.g., 24), or both, are dampened, for example, with a hydraulic or pneumatic damper, with dry friction, or a combination thereof, as examples. In some embodiments, the firearm (e.g., 10, 40) (e.g., the upper receiver (e.g., 11) or the lower receiver (e.g., 12, 42)) is configured with an appropriate fit and tolerance, one or more seals, or both, so that when the bolt assembly (e.g., 28), carrier assembly (e.g., 26, 46), or buffer weight (e.g., 23), (or a combination thereof) move after a round is fired, the bolt assembly (e.g., 28), carrier assembly (e.g., 26, 46), or buffer weight (e.g., 23), (or a combination thereof) traps air that then compresses, flows through the clearance or an orifice, as examples, to absorb recoil energy, dampen motion, or both. Even further, in some embodiments, a bumper or bump stop, for example, made of rubber or an elastomeric material, can be used, for instance, in combination with or instead of a spring. Even further still, in some embodiments, multiple springs can be used where the main buffer spring (e.g., 21) or spindle spring (e.g., 24) is described herein (e.g., 2, 3, or 4 concentric helical springs).

In several embodiments, the firearm (e.g., 10, 40) includes a bolt assembly (e.g., 28). Further, in various embodiments, the firearm (e.g., 10, 40) includes a bolt carrier group (e.g., 27, 47). Even further, in many embodiments, the bolt carrier group (e.g., 27, 47) includes the carrier assembly (e.g., 26, 46). Further still, in particular embodiments, the firearm (e.g., 10, 40) includes a bolt assembly (e.g., 28), a carrier assembly (e.g., 26, 46), a main buffer spring (e.g., 21) aft of carrier assembly (e.g., 26, 46), and a carrier spindle (e.g., 25, 45) between the carrier assembly (e.g., 26, 46) and the main buffer spring (e.g., 21), for example. In some embodiments, the carrier assembly (e.g., 26, 46) is aft of the bolt assembly (e.g., 28), for example. In some embodiments, part of the carrier assembly (e.g., 26, 46) may overlap with part of the bolt assembly (e.g., 28), however. Even further still, in various embodiments, a firearm (e.g., 10, 40) can include other components or assemblies as well, which may be known in the art, such as a barrel (e.g., 13), through which bullets are fired, a chamber, a firing pin, a magazine, a receiver, a stock, a trigger, a trigger mechanism, etc. Further, in many embodiments, the bolt assembly (e.g., 28) includes at least a bolt and the carrier assembly (e.g., 26, 46) includes at least a carrier, but these assemblies can include other components as well. Thus, as used herein, an “assembly” can include one or more different components. In some embodiments, the bolt carrier group (e.g., 27, 47), for example, includes the bolt assembly (e.g., 28), the carrier assembly (e.g., 26, 46), or both. The drawing illustrate examples.

In a number of embodiments, the carrier spindle (e.g., 25, 45) fits inside the carrier assembly (e.g., 26, 46), for example, with a close fit and corresponding tolerance. In some embodiments, for example, a forward end (e.g., 32, 52) of the carrier spindle (e.g., 25, 45) fits inside an aft end (e.g., 39, 59) of the carrier assembly (e.g., 26, 46). Further, in some embodiments, the carrier spindle (e.g., 25, 45) includes a forward end (e.g., 32, 52) and an aft end (e.g., 31, 51). Further still, in a number of embodiments, the aft end (e.g., 31, 51) has a larger major lateral dimension (e.g., 36, 56) than a major lateral dimension (e.g., 37 or 57) at the forward end (e.g., 32, 52) of the carrier spindle (e.g., 25, 45). As used herein, “lateral” means perpendicular to the axis of the barrel (e.g., 13) of the firearm (e.g., 10, 40) or perpendicular to the direction of motion of the carrier assembly (e.g., 26, 46) when the firearm (e.g., 10, 40) is fired. Moreover, as used herein, a “major dimension” of a component means a dimension that extends all the way across at least a portion of the component. An example of a major dimension is a diameter of at least a portion (e.g., a cross section) of the component.

In various embodiments, the carrier spindle (e.g., 25, 45) has a length (e.g., 33, 53) parallel to the axis of the barrel (e.g., 13), and the carrier spindle (e.g., 25, 45) has a forward end (e.g., 32, 52) and an aft end (e.g., 31, 51), and the forward end (e.g., 32, 52) has a uniform major lateral dimension (e.g., 37, 57) over a majority of the length of the carrier spindle (e.g., 25, 45). As used herein, “uniform” means the same to within ten (10) percent of the major lateral dimension (e.g., diameter). In various embodiments, however, the forward end (e.g., 32, 52) of the carrier spindle (e.g., 25, 45) has a uniform major lateral dimension (e.g., 37, 57) over a majority of the length of the carrier spindle (e.g., 25, 45) that is uniform to within 7.5, 5, 4, 3, 2, 1, 0.5, 0.25, 0.2, 0.1, or 0.05 percent of the major lateral dimension (e.g., 37, 57), as other examples. Further, in some embodiments, the uniform lateral dimension (e.g., 37, 57) is a diameter of a circular cross section of the forward end (e.g., 32, 52) of the carrier spindle (e.g., 25, 45). Other embodiments, however, have a different shape cross section, such as a square, a rectangle, a regular polygon, a hexagon, an octagon, a cross, an oval, a star shape, or a splined shape, as examples.

In particular embodiments, the aft end (e.g., 31, 51) of the carrier spindle (e.g., 25, 45) has a circular cross section. Moreover, in particular embodiments, the aft end (e.g., 31, 51) comprises a taper (e.g., 34, 54). This taper (e.g., 34, 54) can be, for example, a variation in major lateral dimension (e.g., 36, 56), such as diameter, from a minimum (e.g., of the aft end 31, 51) at the aftmost surface of the aft end (e.g., 31, 51), varying gradually (e.g., linearly, for instance, concentrically) to a maximum major lateral dimension (e.g., 36, 56) a short distance forward of the aftmost surface. As used herein, the “major lateral dimension” at the aft end, is measured forward of the taper (e.g., 34, 54), on embodiments that include such a taper. In addition, as used herein, in this context, the “short distance forward of the aftmost surface” is less than ⅓ of the major lateral dimension (e.g., 36, 56) at the aft end (e.g., 31, 51) of the carrier spindle (e.g., 25, 45).

In some embodiments, this “short distance forward of the aftmost surface” or the longitudinal dimension of the taper (e.g., 34, 54) is ¼, ⅕, ⅙, or ⅛ of the major lateral dimension (e.g., 36, 56) at the aft end (e.g., 31, 51) of the carrier spindle (e.g., 25, 45), as examples. In some embodiments, this “short distance” or the size of the taper (e.g., 34, 54) can be ⅛, 3/16, 7/32, ¼, 9/32, 5/16, ⅜, 7/16, or ½ inch, as examples (e.g., measured along the taper, for instance, 34, 54, or in a direction parallel to the centerline of the carrier spindle). In various embodiments, the taper (e.g., 34, 54) can be made at an angle of 30, 35, 40, 45, 50, 55, or 60 degrees (e.g., measured from the aftmost surface of the aft end (e.g., 31, 51) or from the centerline of the carrier spindle (e.g., 25, 45), for example, perpendicular to the axis of the barrel (e.g., 13) of the firearm), as examples.

In certain embodiments, the taper (e.g., 34, 54) extends all the way around the aft end (e.g., 31, 51) of the carrier spindle (e.g., 25, 45). Further, in particular embodiments, the carrier spindle (e.g., 25, 45), taper (e.g., 34, 54), or both, is symmetrical about a centerline, for example, of the carrier spindle (e.g., 25, 45) that is parallel to or concentric with the centerline of the barrel (e.g., 13) of the firearm (e.g., 10, 40). In other embodiments, however, the taper (e.g., 34, 54) can be present only on the top of the carrier spindle (e.g., 25, 45), only on the top half of the carrier spindle (e.g., 25, 45), or on the top and bottom of the carrier spindle (e.g., 25, 45) but not the sides of the carrier spindle (e.g., 25, 45), as other examples. In various embodiments, however, the taper (e.g., 34) is present at least on the top of the carrier spindle (e.g., 25, 45).

In various embodiments, the firearm (e.g., 10, 40) includes an upper receiver (e.g., 11) and a lower receiver (e.g., 12, 42). In some such embodiments, the taper (e.g., 34, 54) pushes the carrier spindle (e.g., 25, 45) forward (e.g., away from the buffer weight, for instance, 23) when the upper receiver (e.g., 11) is separated from the lower receiver (e.g., 12, 42). In a number of embodiments, the upper receiver (e.g., 11) moves upward relative to the lower receiver (e.g., 12, 42) when the upper receiver and the lower receiver are separated. For example, in some embodiments, the upper receiver (e.g., 11) is pivotably attached to the lower receiver (e.g., 12, 42), for instance, below the forward end of the bolt carrier group (e.g., 27, 47) or the bolt assembly (e.g., 28), and the taper (e.g., 34, 54) pushes the carrier spindle (e.g., 25, 45) forward when the upper receiver (e.g., 11) is pivoted (e.g., upward) relative to the lower receiver (e.g., 12, 42). In a number of embodiments, the taper (e.g., 34, 54) pushes against part of the lower receiver (e.g., 12, 42), which pushes the carrier spindle (e.g., 25, 45) forward, for example, against the spindle spring (e.g., 24). In various embodiments, this makes the firearm (e.g., 10, 40) easier to open than certain prior art alternatives. In a number of embodiments, the spindle spring (e.g., 24) pushes the carrier spindle aft when the upper receiver and the lower receiver are fully separated or when the upper receiver is mated to the lower receiver.

Further, in some embodiments, when the firearm (e.g., 10, 40) is ready to be fired, at least a portion of the aft end (e.g., 31, 51) of the carrier spindle (e.g., 25, 45) or at least a portion of the taper (e.g., 34, 54) extends into the lower receiver (e.g., 12, 42), for instance, aft of the upper receiver (e.g., 11) at this location along the firearm. In a number of embodiments, when the firearm (e.g., 10, 40) is ready to be fired, a majority of the carrier spindle (e.g., 25, 45) is located in the upper receiver (e.g., 11), however.

Moreover, in certain embodiments that include a spindle spring (e.g., 24) that biases the carrier spindle (e.g., 25, 45) aftward, when the taper (e.g., 34) pushes the carrier spindle (e.g., 25, 45) forward, the spindle spring (e.g., 24) is compressed (e.g., at least partially compressed, for instance, more compressed (e.g., at least momentarily) than if the firearm (e.g., 10, 40) were not opened. Furthermore, in some embodiments, when the firearm (e.g., 10, 40) is discharged, the carrier spindle (e.g., 25, 45) moves further into the lower receiver (e.g., 12, 42). Still further, in some embodiments, the firearm (e.g., 10, 40) includes a buffer tube (e.g., 22), for instance, in the lower receiver (e.g., 12, 42), and when the firearm (e.g., 10, 40) is discharged, the carrier spindle (e.g., 25, 45) guides the carrier assembly (e.g., 26, 46) into the buffer tube (e.g., 22), for example, partially into the buffer tube (e.g., 22). For example, in a number of embodiments, the aft end (e.g., 31, 51) of the carrier spindle (e.g., 25, 45) fits inside the buffer tube (e.g., 22) and has a close tolerance with the buffer tube (e.g., 22) and controls lateral motion of the aft end (e.g., 31, 51) of the carrier assembly (e.g., 26, 46) or the bolt carrier group (e.g., 27, 47), for instance, when the firearm (e.g., 10, 40) is discharged, when the buffer spring returns the carrier assembly (e.g., 26, 46) or the bolt carrier group (e.g., 27, 47) forward, or both.

Certain embodiments include various firearms (e.g., 10, 40) that each include, for example, a carrier assembly (e.g., 26, 46), a carrier spindle (e.g., 25, 45), and a spindle spring (e.g., 24). In a number of embodiments, a helical spindle spring (e.g., 24), for example, is located between the carrier spindle (e.g., 25, 45) and the carrier assembly (e.g., 26, 46). Further, in a number of embodiments, the spindle spring (e.g., 24), pushes the carrier spindle (e.g., 25, 45), for instance, aftward, away from the carrier assembly (e.g., 26, 46), or both. In various embodiments, for example, the (e.g., helical) spindle spring (e.g., 24) is loaded in compression. Moreover, in a number of embodiments, the carrier spindle (e.g., 25, 45) is at least partially aft of the carrier assembly (e.g., 26, 46). Further, in various embodiments, the carrier spindle (e.g., 25, 45) slidably engages the carrier assembly (e.g., 26, 46).

Further, as mentioned, some embodiments include a buffer weight (e.g., 23), a main buffer spring (e.g., 21), or both. In a number of embodiments, for example, the buffer weight (e.g., 23) is aft of the carrier spindle (e.g., 25, 45), the main buffer spring (e.g., 21) is aft of the buffer weight (e.g., 23), or both. Further still, in various embodiments the main buffer spring (e.g., 21) is aft of the carrier assembly (e.g., 26, 46). Even further, in some embodiments, the main buffer spring (e.g., 21) is stiffer than the (e.g., helical) spindle spring (e.g., 24). Still further, in a number of embodiments, the carrier spindle (e.g., 25, 45) fits inside the carrier assembly (e.g., 26, 46) when the firearm (e.g., 10, 40) is assembled. An example is illustrated in the drawings.

Various embodiments include, for example, a barrel (e.g., 13) through which bullets are fired. In some embodiments, for instance, the carrier spindle (e.g., 25, 45) includes a length (e.g., 33, 53) parallel to an axis of the barrel (e.g., 13), a forward end (e.g., 32, 52), and an aft end (e.g., 31, 51), and the aft end (e.g., 31, 51) has a larger major lateral dimension (e.g., 36, 56) than the forward end (e.g., major lateral dimension 37, 57 at forward end 32, 52). Moreover, in some embodiments, the forward end (e.g., 32, 52) has a uniform major lateral dimension (e.g., 37, 57) over a majority of the length (e.g., 33, 53) of the carrier spindle (e.g., 25, 45). Further, in some embodiments, the aft end (e.g., 31, 51) of the carrier spindle (e.g., 25, 45) includes a taper (e.g., 34, 54). Still further, in a number of embodiments, the firearm (e.g., 10, 40) includes an upper receiver (e.g., 11) and a lower receiver (e.g., 12, 42).

Even further, in certain embodiments, the taper (e.g., 34, 54) pushes the carrier spindle (e.g., 25, 45) forward when the upper receiver (e.g., 11) is separated (e.g., pivoted) from the lower receiver (e.g., 12, 42). In some embodiments, the firearm (e.g., 10, 40) includes a buffer tube (e.g., 22). Further, in various embodiments, when the firearm (e.g., 10, 40) is discharged, the carrier spindle (e.g., 25, 45) guides the carrier assembly (e.g., 26, 46) into the buffer tube (e.g., 22), the carrier spindle (e.g., 25, 45) acts to reduce carrier tilt within the firearm, or both. Further, certain embodiments include, for example, a raised carrier saddle (e.g., 60) that supports an aft end (e.g., 59) of the carrier assembly (e.g., 46), for example, in addition to other components described above. Other embodiments, however, include a carrier saddle (e.g., 60) that supports an aft end (e.g., 59) of the carrier assembly (e.g., 46), but do not necessarily include other components described above.

Particular embodiments include various firearms that include, for example, a carrier assembly (e.g., 46), a buffer spring (e.g., 21), and a carrier saddle (e.g., 60), for instance, that supports the aft end (e.g., 59) of the carrier assembly (e.g., 46). In certain such embodiments, for example, the carrier assembly (e.g., 46) has an aft end (e.g., 59), and the buffer spring (e.g., 21) biases the carrier assembly (e.g., 46) forward. Moreover, in various embodiments, the carrier saddle (e.g., 60) that supports the aft end (e.g., 59) of the carrier assembly (e.g., 46) is raised (e.g., a raised carrier saddle), for instance, raised from the adjacent interior surface of the lower receiver (e.g., 42). In various embodiments, the carrier saddle (e.g., 60) partially or fully prevents the carrier assembly (e.g., 46) or bolt carrier group (e.g., 47) from tilting, for example, when the carrier assembly (e.g., 46) or bolt carrier group (e.g., 47) is moving, for instance, back and forth when the firearm (e.g., 40) is fired.

A number of embodiments further include, for example, a buffer weight (e.g., 23), for instance, aft of the carrier assembly (e.g., 46). Further, in some embodiments, the buffer spring is aft of the buffer weight (e.g., 23). Still further, in various embodiments, the firearm (e.g., 40) includes an upper receiver (e.g., 11) and a lower receiver (e.g., 42). Even further, in some embodiments, the lower receiver (e.g., 42) includes the (e.g., raised) carrier saddle (e.g., 60). Further still, in certain embodiments, for instance, the carrier saddle (e.g., 60) is integrated into or integral with the lower receiver (e.g., 42). In other embodiments, however, the carrier saddle is a separate piece from the lower receiver, for example, attached to the lower receiver. In certain embodiments, the height of the carrier saddle is adjustable, for example, to adjust clearance, to guide the carrier assembly (e.g., 46) into the buffer tube (e.g., 22), to reduce carrier tilt within the firearm, or a combination thereof, as examples. In various embodiments, the firearm (e.g., 40) includes a buffer tube (e.g., 22), and when the firearm (e.g., 40) is discharged, the (e.g., raised) carrier saddle (e.g., 60) guides the carrier assembly (e.g., 46) into the buffer tube (e.g., 22). Moreover, in various embodiments, the (e.g., raised) carrier saddle (e.g., 60) acts to reduce carrier tilt within the firearm.

In some embodiments, the carrier saddle (e.g., 60) includes a concave top surface (e.g., 61) (e.g., raised) that supports, for example, the aft end (e.g., 59) of the carrier assembly (e.g., 46). In some such embodiments, for example, the top surface (e.g., 61) is concave when viewed from the forward end or rearward end (e.g., via a cross section of the firearm), for instance, as shown. In the embodiment illustrated, however, the top surface (e.g., 61) does not appear to be concave when viewed from the side (e.g., right side or left side, for instance, via a cross section of the firearm).

Further, in some embodiments, the top surface (e.g., 61) of the carrier saddle (e.g., 60), for instance, that supports the aft end (e.g., 59) of the carrier assembly (e.g., 46), includes an overall top surface (e.g., 61) lateral dimension (e.g., 62), for instance, measured in a horizontal direction, that is between 25 percent and 75 percent of an overall lateral dimension (e.g., 58) of the carrier assembly (e.g., 46) at the aft end (e.g., 59). Further still, in some embodiments, the top surface (e.g., 61) of the carrier saddle (e.g., 60), includes an overall top surface (e.g., 61) lateral dimension (e.g., 62), measured in a horizontal direction, that is between 10 percent and 90 percent, between 20 and 80 percent, between 30 and 70 percent, or between 40 and 60 percent of the overall lateral dimension (e.g., 58) of the carrier assembly (e.g., 46) at the aft end (e.g., 59), as examples, or that is less than the larger end of such ranges.

Still further, in some embodiments, the top surface (e.g., 61) that supports the aft end (e.g., 59) of the carrier assembly (e.g., 46) includes an overall top surface (e.g., 61) longitudinal dimension (e.g., 63) that is less than the overall lateral dimension (e.g., 58) of the carrier assembly (e.g., 46) at the aft end (e.g., 59). As used herein, a “longitudinal dimension” (e.g., 63) is measured parallel to the axis of the barrel (e.g., 13) of the firearm. Even further, in some embodiments, the overall top surface (e.g., 61) longitudinal dimension (e.g., 63) is between ⅛ inch and the overall lateral dimension (e.g., 58) of the carrier assembly (e.g., 46) at the aft end (e.g., 59), for example. In certain embodiments, the overall top surface (e.g., 61) longitudinal dimension (e.g., 63) is greater than ¼, ⅜, ½, ⅝, or ¼ inch, as other examples. Even further still, in particular embodiments, the overall top surface (e.g., 61) longitudinal dimension (e.g., 63) is less than 90, 80, 70, 60, 50, or 40 percent of the overall lateral dimension (e.g., 58) of the carrier assembly (e.g., 46) at the aft end (e.g., 59) as other examples.

Even further, in various embodiments, the (e.g., raised) carrier saddle (e.g., 60) comprises or consists of a material having a lower hardness than a hardness of the carrier assembly (e.g., 46) at the aft end (e.g., 59). In some embodiments, for example, the carrier saddle is aluminum and the carrier assembly is steel. Still further, in certain embodiments, the carrier saddle (e.g., 60) comprises or consists of a material having a significantly lower hardness than a hardness of the carrier assembly (e.g., 46) at the aft end (e.g., 59). As used herein, a “significantly lower hardness” means less than half of the hardness. In some embodiments, the carrier saddle may comprise a low friction material, a lubricant (e.g., a solid lubricant), a lubricant delivery system (e.g., including a grease or oil passage), or a combination thereof.

In various embodiments, a firearm (e.g., 40) includes, for example, an upper receiver (e.g., 11), a lower receiver (e.g., 42), a carrier assembly (e.g., 46), a buffer spring (e.g., 21), and a raised carrier saddle (e.g., 60). In a number of embodiments, for example, the lower receiver (e.g., 42) includes a buffer tube (e.g., 22), the carrier assembly (e.g., 46) is located in the upper receiver (e.g., 11), the carrier assembly (e.g., 46) has an aft end (e.g., 59), or a combination thereof. Further, in various embodiments, the buffer spring (e.g., 21) is located in the buffer tube (e.g., 22), in the lower receiver (e.g., 42), aft of the aft end (e.g., 59) of the carrier assembly (e.g., 46), or a combination thereof. Still further, in a number of embodiments, the raised carrier saddle (e.g., 60) supports the aft end (e.g., 59) of the carrier assembly (e.g., 46). Even further, in various embodiments, for instance, when the firearm (e.g., 40) is discharged, the raised carrier saddle (e.g., 60) guides the carrier assembly (e.g., 46), for example, into the buffer tube (e.g., 22), the raised carrier saddle (e.g., 60) acts to reduce carrier tilt within the firearm, or both. In a number of embodiments, the firearm (e.g., 40) includes a carrier spindle (e.g., 45), but in other embodiments, a firearm having a (e.g., raised) carrier saddle (e.g., 60), may omit a carrier spindle (e.g., 45), carrier spring (e.g., 24), or both.

Other embodiments, besides firearms, include buffer systems (e.g., 40, 50) for firearms. Such a firearm (e.g., 10, 40) can include a bolt assembly (e.g., 28) and a carrier assembly (e.g., 26, 46), for example, or a bolt carrier group (e.g., 27, 47). In some embodiments, the buffer system (e.g., 40, 50), includes a main buffer spring (e.g., 21), for instance, aft of the carrier assembly (e.g., 26, 46), and a spindle spring (e.g., 24), for example, between the carrier assembly (e.g., 26, 46) and the main buffer spring (e.g., 21). Such a buffer system (e.g., 40, 50), or a firearm (e.g., 10, 40) containing such a buffer system, can further include, in particular embodiments, a combination (e.g., any combination) of the features recited herein, or known in the art, for instance, for a firearm. In some embodiments, for example, the firearm (e.g., 10, 40) includes a bolt carrier group (e.g., 27, 47), and the buffer system (e.g., 40, 50) includes a main buffer spring (e.g., 21) aft of the bolt carrier group (e.g., 27, 47), a buffer weight (e.g., 23) forward of the main buffer spring (e.g., 21), and a carrier spindle (e.g., 25, 45) between the bolt carrier group (e.g., 27, 47) and the buffer weight (e.g., 23). Buffer systems (e.g., 40, 50) can include other features described herein. All different combinations are contemplated.

Still other embodiments include certain methods that pertain to buffer systems (e.g., 40, 50) for firearms. Further, particular methods can include acts of obtaining or providing, as examples, other features, components, or aspects described herein. All possible combinations are contemplated. Further, methods described herein contain various acts. The order in which these acts are described herein may be an example of the order in which these acts can be performed, but in other embodiments, unless stated otherwise herein or precluded by other factors, the acts may be performed in a different order. In some embodiments, acts may overlap or be performed at the same time, as another example.

Particular embodiments include certain methods of absorbing recoil energy of a firearm (e.g., 10, 40), for instance. Such a method can include, for example, at least the acts of: obtaining or providing a main buffer spring (e.g., 21), and obtaining or providing a carrier spindle (e.g., 25, 45). Further, some methods include an act of obtaining or providing a (e.g., raised) carrier saddle (e.g., 60), for example, instead of, or in addition to, a carrier spindle (e.g., 25, 45). Further, some embodiments (e.g., having a carrier spindle) include obtaining or providing a spindle spring (e.g., 24). In some embodiments, the method further includes locating the main buffer spring (e.g., 21) aft of a carrier assembly (e.g., 26, 46) of the firearm. Further, in a number of embodiments, the method further includes locating the spindle spring (e.g., 24) aft of a bolt assembly (e.g., 28) of the firearm (e.g., 10, 40) or a bolt carrier group (e.g., 27, 47). Further still, in some embodiments, the method further includes locating the spindle spring (e.g., 24) aft of a carrier assembly (e.g., 26, 46) of the firearm. Different embodiments include some or all of such acts.

Yet other embodiments include various methods of making a firearm (e.g., 10, 40) easier to be used (e.g., at least by certain people). Such a method can include, for example, obtaining, providing, or manufacturing the firearm (e.g., 10, 40) having a bolt assembly (e.g., 28), a carrier assembly (e.g., 26, 46), a main buffer spring (e.g., 21), for instance, aft of the carrier assembly (e.g., 26, 46), a carrier spindle (e.g., 25, 45), and a spindle spring (e.g., 24), for example, between the carrier spindle (e.g., 25, 45) and the carrier assembly (e.g., 26, 46). In different embodiments, a method (e.g., as described herein) further includes acts of obtaining or providing a combination of the components or features recited herein (e.g., above). All applicable combinations are contemplated. Various methods can further include acts of manufacturing other components described herein, shown on the drawings, or both.

Other methods include certain methods of reducing carrier tilt within a firearm (e.g., 10, 40) having a carrier (e.g., carrier assembly 46, 46), a buffer weight (e.g., 23), a buffer spring (e.g., 21), an upper receiver (e.g., 11), and a lower receiver (e.g., 12, 42). Such a method can include, for instance, at least the acts of obtaining or providing a carrier spindle (e.g., 25, 45), and locating the carrier spindle (e.g., 25, 45) between a buffer weight (e.g., 23) and the carrier. In a number of embodiments, the carrier spindle (e.g., 25, 45) and the buffer weight (e.g., 23) are separate pieces that separate (i.e., come apart) when the upper receiver (e.g., 11) and the lower receiver (e.g., 12, 42) are separated (i.e., in a normal process of disassembly of the weapon for service or inspection). Some embodiments include an act of obtaining or providing a taper (e.g., 34, 54) on the carrier spindle (e.g., 25, 45) or an act of obtaining or providing a carrier spindle (e.g., 25, 45) having taper (e.g., 34, 54), for instance, as described herein. Further, various methods include acts of obtaining or providing a combination of the features or limitations recited herein.

Furthermore, in various of the firearms, buffer systems, and methods contemplated, the carrier spindle (e.g., 25, 45), carrier saddle (e.g., 60), or both, acts to reduce carrier tilt within the firearm. Further, in some embodiments, the carrier spindle (e.g., 25, 45), carrier saddle (e.g., 60), or both, acts to reduce carrier wobble within the firearm, acts to reduce carrier misalignment within the firearm, acts to reduce wear within the firearm, specifically acts to reduce buffer tube (e.g., 22) wear within the firearm, or a combination thereof. In still other specific embodiments, a firearm (e.g., 10, 40) includes a carrier assembly (e.g., 26, 46), an upper receiver (e.g., 11), a lower receiver (e.g., 12, 42), and a carrier spindle (e.g., 25, 45) that is at least partially aft of the carrier assembly (e.g., 26, 46). In a number of embodiments, the carrier spindle (e.g., 25, 45) includes a tapered (e.g., taper 34, 54) portion that pushes the carrier spindle (e.g., 25, 45) forward when the upper receiver (e.g., 11) is separated from the lower receiver (e.g., 12, 42).

In further embodiments, a firearm (e.g., 10, 40) includes an upper receiver (e.g., 11), a lower receiver (e.g., 12, 42), a bolt carrier group (e.g., 27, 47) located at least partially within the upper receiver (e.g., 11), a main buffer spring (e.g., 21) located within the lower receiver (e.g., 12, 42) aft of the bolt carrier group (e.g., 27, 47), a buffer weight (e.g., 23) located within the lower receiver (e.g., 12, 42) aft of the bolt carrier group (e.g., 27, 47) and forward of the main buffer spring (e.g., 21), and a carrier spindle (e.g., 25, 45) that is at least partially aft of the bolt carrier group (e.g., 27, 47). Such firearms can further include other features described herein. In a number of embodiments, a firearm includes a sub-combination of the components or features described herein. Further, various embodiments include other combinations of the features described herein. All feasible combinations are contemplated.

In a number of embodiments of a firearm, buffer system, or method, as examples, the spindle spring (e.g., 24) acts to reduce peak recoil force produced by the firearm. Further, in some embodiments of a firearm, buffer system, or method, for instance, the spindle spring (e.g., 24) acts to absorb recoil energy produced by the firearm. Specifically, in certain embodiments, the spindle spring (e.g., 24) acts to absorb recoil energy produced by the firearm (e.g., 10, 40) not otherwise absorbed by the main buffer spring (e.g., 21). Further, in particular embodiments, more of the recoil energy is absorbed by the firearm (e.g., 10, 40) rather than by the operator, for example, in comparison with the firearm (i.e., the same firearm) without the spindle spring (e.g., 24).

In a number of embodiments, the firearm (e.g., 10, 40) is a rifle. In particular embodiments, for example, the firearm (e.g., 10, 40) is an assault rifle, such as an AR-15 or an M-16. In some embodiments, the firearm (e.g., 10, 40) can be a semi-automatic firearm (e.g., 10, 40) or a fully automatic firearm, as examples. Further, in particular embodiments, the firearm is a rifle configured to selectably (e.g., via operation of a selector lever) fire in a fully-automatic mode and in a semi-automatic mode. Other embodiments, however, may differ. For instance, in particular embodiments the firearm (e.g., 10, 40) can be a pistol.

Further, various embodiments of the subject matter described herein include various combinations of the acts, structure, components, and features described herein, shown in the drawings, described in documents that are incorporated by reference herein, or that are known in the art. Moreover, certain procedures can include acts such as manufacturing, obtaining, or providing components that perform functions described herein or in the documents that are incorporated by reference. The subject matter described herein also includes various means for accomplishing the various functions or acts described herein, in the documents that are incorporated by reference, or that are apparent from the structure and acts described. Each function described herein is also contemplated as a means for accomplishing that function, or where appropriate, as a step for accomplishing that function.

Further still, as used herein, the word “or”, except where indicated otherwise, does not imply that the alternatives listed are mutually exclusive. Even further, where alternatives are listed herein, it should be understood that in some embodiments, fewer alternatives may be available, or in particular embodiments, just one alternative may be available, as examples. 

What is claimed is:
 1. A firearm comprising: a carrier assembly; a carrier spindle that is at least partially aft of the carrier assembly, wherein the carrier spindle slidably engages the carrier assembly; and a helical spindle spring located between the carrier spindle and the carrier assembly that pushes the carrier spindle aftward, away from the carrier assembly, wherein the helical spindle spring is loaded in compression.
 2. The firearm of claim 1 further comprising a buffer weight aft of the carrier spindle and a main buffer spring aft of the buffer weight.
 3. The firearm of claim 1 further comprising a main buffer spring aft of the carrier assembly wherein the main buffer spring is stiffer than the helical spindle spring.
 4. The firearm of claim 1 wherein the carrier spindle fits inside the carrier assembly when the firearm is assembled.
 5. The firearm of claim 1 comprising a barrel through which bullets are fired, wherein: the carrier spindle comprises a length parallel to an axis of the barrel, a forward end, and an aft end; the aft end has a larger major lateral dimension than the forward end; and the forward end has a uniform major lateral dimension over a majority of the length of the carrier spindle.
 6. The firearm of claim 1 wherein: the carrier spindle comprises a forward end and an aft end; the aft end comprises a taper; the firearm comprises an upper receiver and a lower receiver; and the taper pushes the carrier spindle forward when the upper receiver is separated from the lower receiver.
 7. The firearm of claim 1 wherein: the firearm comprises a buffer tube; when the firearm is discharged, the carrier spindle guides the carrier assembly into the buffer tube; and the carrier spindle acts to reduce carrier tilt within the firearm.
 8. The firearm of claim 1 further comprising a raised carrier saddle that supports an aft end of the carrier assembly.
 9. A firearm comprising: a carrier assembly having an aft end; a buffer spring that biases the carrier assembly forward; and a raised carrier saddle that supports the aft end of the carrier assembly.
 10. The firearm of claim 9 further comprising a buffer weight aft of the carrier assembly, wherein the buffer spring is aft of the buffer weight.
 11. The firearm of claim 9 wherein the firearm comprises an upper receiver and a lower receiver and the lower receiver comprises the raised carrier saddle.
 12. The firearm of claim 11 wherein the raised carrier saddle is integral with the lower receiver.
 13. The firearm of claim 9 wherein: the firearm comprises a buffer tube; and when the firearm is discharged, the raised carrier saddle guides the carrier assembly into the buffer tube.
 14. The firearm of claim 9 wherein the raised carrier saddle acts to reduce carrier tilt within the firearm.
 15. The firearm of claim 9 wherein the raised carrier saddle comprises a concave top surface that supports the aft end of the carrier assembly.
 16. The firearm of claim 9 wherein: the raised carrier saddle comprises a top surface that supports the aft end of the carrier assembly; and the raised carrier saddle comprises an overall top surface lateral dimension that is between 25 percent and 75 percent of an overall lateral dimension of the carrier assembly at the aft end.
 17. The firearm of claim 9 wherein: the raised carrier saddle comprises a top surface that supports the aft end of the carrier assembly; and the raised carrier saddle comprises an overall top surface longitudinal dimension that is between ⅛ inch and an overall lateral dimension of the carrier assembly at the aft end.
 18. The firearm of claim 9 wherein the raised carrier saddle consists of a material having a significantly lower hardness than a hardness of the carrier assembly at the aft end.
 19. The firearm of claim 9 wherein: the firearm comprises an upper receiver and a lower receiver; the lower receiver comprises the raised carrier saddle; the lower receiver comprises a buffer tube; when the firearm is discharged, the raised carrier saddle guides the carrier assembly into the buffer tube; the raised carrier saddle acts to reduce carrier tilt within the firearm; the raised carrier saddle comprises a concave top surface that supports the aft end of the carrier assembly; the raised carrier saddle comprises an overall top surface lateral dimension that is between 25 percent and 75 percent of an overall lateral dimension of the carrier assembly at the aft end; and the raised carrier saddle comprises an overall top surface longitudinal dimension that is less than the overall lateral dimension of the carrier assembly at the aft end; and the raised carrier saddle consists of a material having a lower hardness than a hardness of the carrier assembly at the aft end.
 20. A firearm comprising: an upper receiver; a lower receiver comprising a buffer tube; a carrier assembly located in the upper receiver, the carrier assembly having an aft end; a buffer spring located in the buffer tube in the lower receiver and aft of the aft end of the carrier assembly; and a raised carrier saddle that supports the aft end of the carrier assembly wherein: when the firearm is discharged, the raised carrier saddle guides the carrier assembly into the buffer tube and the raised carrier saddle acts to reduce carrier tilt within the firearm. 